I get 32-34 mpg no matter how I ride the bike around town. I will be satisfied if I can get 40.

Flick, thanks for the tips on that valve. Bike is back together and it sounds and runs good. It seems be accelerate quicker and throttle response is snappier, it also seems to chug less at low rpms. I hope this helps my fuel economy. The guy at the parts place looked at my plug, and with mods bike has recommended a 165 main. Ill run ~50 miles with valve adjustment and re calculate mileage to see if it will help. If not ill try that bigger main.

So the valve adjustment increased mileage by about 1 mpg. I got 35 for the last 70 miles. I threw in the 165 main, an the engine ran down here (5000') like it does at 8000' with the 155. I think I'll try a 150 main. Also, what is the function of mixing screw, I can't seem to notice what it does when I adjust it. Also, my carb kit came with two o-rings one for the tip of mixing screw near the spring and another is supposed to go somewhere on shaft according to the parts diagram but I can't figure out where, it is also a larger diameter. There was no existing one to compare to. Any recommendations on a high flow air filter? Can anyone else think why my mileage is so bad? I can incorrect jetting really throw off mileage by 15mpg?